Electron beam columns are used in scanning electron microscopes (SEMs) that image objects and in lithography tools for writing patterns onto semiconductor materials to be used as integrated circuits. Conventional electron beam columns consist of an assembly of components, including lenses and magnets, individually machined out of stainless steel or other alloys and individually assembled, and an electron source. A new electron beam column consisting of a package, microfabricated components, and electron source is proposed. The ideal package for this new column should meet the following criteria:    1. The package, including all the internal and external features required for electron beam column operation, should be scalable to small dimensions.    2. The packaging technology should be capable of printing the interconnects and the required shielding on the compact package with sufficient line widths and spacing to eliminate short and long term failures due to electrical break down or other failure mechanisms like, for example, electromigration.    3. The package should support controlled impedance lines and terminations for high-speed interconnects to deflectors, blankers, and other high-speed column components. These impedance lines are typically strip-line or micro-strip-line in configuration with impedances ranging from about 15 to about 150 Ohms.    4. The package should support embedded passive and active devices for on-board drivers, power supplies, monitors, diagnostics, processing, calibration, identification and other electronic functions. This configuration minimizes external circuitry, reduces the number of feed through connections, and allows termination using components mounted directly on the package.    5. The package should support mounting high-speed drivers in close proximity to the electrodes enabling GHz operation.    6. The package should be amenable to production assembly of the components. All connections to the external world should be accessible to pick and place, wire bonding, or other assembly tools. For example, all interconnects might terminate on sufficiently large pads (typically 250×250 um) located on the topside of the package.    7. The package should be amenable to batch fabrication to minimize production costs.    8. The package should be rigid, mechanically hard, and durable to provide an adequate platform for imaging and, perhaps lithography, and able to survive the rigors of in-field operation and, perhaps, space flight.    9. The package coefficient of thermal expansion (CTE) should be closely matched to all other materials that it is in contact with to prevent drift, misalignment, distortions, fatigue, and other fatal occurrences.    10. The package should be attachable to the housing material, typically aluminum or stainless steel with a hermetic seal using welding, brazing, soldering or epoxy bonding. The package should allow intermediate, CTE transitioning layers, to be patterned on the surface for this purpose, such as, KOVAR.    11. The package should have a sufficiently high breakdown voltage to be electrically reliable and isolated while meeting volume constraints required by the compact design.    12. The package total thickness variation (TTV), flatness and roughness should be minimized to minimize the distortions and aberrations of the assembled column. The package should have, for example, a TTV<±1 mil, flatness <±0.5 mil/in, and RMS roughness <±0.04 mil.    13. The package may be UHV compatible.    14. The electrical interconnects printed internal to the package should be hermetically sealed to improve reliability.    15. The package must be scalable to support multiple electron beam columns in an arrayed assembly.
Conventional electron beam columns and the packages or support apparatus of other embodiments of miniature electron beam columns fail to meet most of these criteria.
Accordingly, a package enabling the proposed new electron beam column and method of use thereof is required that can overcome deficiencies of conventional electron beam columns and past embodiments of miniature electron beam columns by meeting at least some of the above-mentioned criteria.